Material rendering fuzzy on some objects and not others
Your problem is that several of your petals are duplicated exactly on top of themselves.  Since the petals are super high poly the z-fighting is not quite as obvious as usual.

This probably happened because you pressed Shift(or Alt)+D and then exited the operator with a right click (or by pressing Esc).  This does not cancel the entire duplication operation, it just cancels the translation and drops the duplicate directly on top of the old one.

To fix this just select and delete all the unintentional duplicates.  I would do this by selecting each problematic petal and checking if it has a material assigned to it, if not delete it; if so right click it again to select its duplicate, then delete it.